Clutch.



M. L. JOHNSTON.

CLUTCH.

APPLICATION FILED APE/1.19M.

Patented Oct. 30, 1917.

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INVENTOR M ILLARB .L. JOHNSTON WITNESSES MM ATTORNEY metres 1.. Joiins'ron, or arm, New 12031;. g

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To all tuhom it may concern:

Be it known that I, MILLARD JOHN STON, acitizen ofthe United States, residing at Utica, in the county of Oneida and,

State-of New York, have invented certain new and useful Improvements in Clutches,- of which. the following is a specification,

reference. being had therein to the accom panylng drawing.

My invention relates to, a clutch and I de-. cla're' the followngto be a full, concise, and exact: description thereof suflicient to enable anyone skilled in the art to which it ,appertains' to make, and use the. same, reference being had to the accompanying drawings in which like reference charactersrefer to like parts throughout the specification.

The object of the invention 1s. to: providea simple, efficient clutch adapted more par-,

ticularly for use in connection with the platen roller of a typewriter. The clutchv is;

so constructed that. by the. mere manipulation of a handle,;the ratchet wheel will be automatically released, whereby the platen roller may be free to turn in. either direction for the convenience of the typewriter operator.

I attain these. objects the mechanism.

disclosed in the following drawings in which: a

Figure 1 is. a side elevation of the clutch, showing thea s'ame assembled to roller in section; r

Fig. 2 is an enlarged vertical section of the clutch and shaft of the platen roller;

Fig. 3. is a detail perspective view of a thimble employed;

Fig. & is a detail perspective view of the head of a plunger employed;

Fig. 5 is an enlarged. plan view of the clutch, looking in the direction; of the arrow, and showing a section taken on the line 55 of Fig; 2; 1

Fig. 6 is a fragmentary detail view in section, showing certain holes in the head of a plunger employed.

Referring more particularly to the drawings, the clutch is assembled to one end of a shaft 1- passing through the center of the platen roller 2 adapted to revolve therewith. The end of the shaft 1 is recessed at 3 for the disposition of the coiled spring 4:, that normally presses against the head 5 of the plunger having an extension 6 to which is secured by a set screw 7 a handle 8. The end of the recess 3 is closed by aipla'ten a 9-, screw threaded interiorly to. the

SpecificationofLetters fatent. I Application fi1edApri1-4, 1914. Serial No. 829,412.

recess 3 and having. arr-aperture; for the-pas. sage-i'of the extens on 6 of the, plunger.v The roller 2; is recessed at 10 for the housing of The the member 11 of the clutch casing.

memberllhas alo'ose-bearing,at12onthe shaft 1-r',,and is threaded at 13, for the mounting of the ratchet member 14-. There is also a member 15 having aloose bearing tension 6 at 17, and is likewise screw thread- The members 11 and 15 are assembled to the ratchet 14-, in such a manner that there is formed a circumferential recess 19 adapted:

ed at 1 8 for the mounting of the ratchet'lh for the reception of the ends 20 of the; dogs- 21,. whose opposite ends 22 areleosely held in theholkes 23 formed inthehead 5 of the plunger. Thememberll is. prevented from sliding off. the end of the shaft, 1-.. by the thimble 24, which abuts at one end. against the inner surfaceof the member 11 and at 3 its opposite end agamst the circumferential;

shoulder 25vformedb-y the cutting. or ii lli'ng."

of theend of the. shaft The thimblge- 24is: provided with orifices: 26 corresponding,'i111-. size. to the orifices27 formedv in the 27 permit the forward movement of the likewise disposedin the" recess-3 "and held dogs2 l, when the plunger is actuated for-1 1 ward by; the manipulationof thehanclle- 8.

The operation of the device is effected by. assembling the coiled; spring 4; in. the recess 3 of the shaft 1., so astoahear or press 7 against the head. of. the plunger, which is! therein by the 'pl'ugt). The-membersill and 15 are also assembled upon. the shaft f.l

in such aima-nner that they may freely rotate thereon, The said: members 1'1 ,a-nd2-15 ..are-;i,

held ,inposition on. the end of the shaft. v 1 by the thimble 24, which is sprung into.position andrby the: shoulder '36: of the I memhe'r'15. The dogs 21 are disposed in position with their ends 22 loosely held in the holes 23 in the head 5 and their ends 20 in the recess 19. The walls of the holes 23 are tapered or inclined as at 32, whereby to pershaft 1 and the platen roller-2.

represented by 'the dotted lines inFig. 2, in

which position the ends 20 of the dogs 21 will lie parallel with the sides of the recess 19' and be disengaged therefrom along the lines 35 and 36. Upon withdrawing the hand from the handle 8, the spring 4 will normal position, as shown by full lines in Fig. 2, where the ends 20 of the dogs 21 will again engage the members 11 and 15 and throw the ratchet into actuation with the The ends 22 of the dogs 21 are rounded off at 40 to minimize the surface of the ends 20 of the dogs 21 for contact with the sides of the recess 19.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a clutch a ratchet wheel, dogs, having their free ends rounded off, whereby to minimize the surface of contact, for engaging said ratchet wheel, whereby said wheel will be rotated, and a plunger for releasing said dogs from engaging with said ratchet wheel. p

2. In a clutch for typewriters, a ratchet wheel, a casing assembled to a shaft, a thimble for holding said casing in assembled position on said shaft, dogs loosely mounted in said casing and having their free ends 'rounded oif, whereby to minimize the surface of contact, means whereby said dogs will engage said casing, whereby said ratchet wheel will-turn with said shaft, and a plunger for releasing said dogs from engagement with said casing, whereby said ratchet wheel will turn independently of said shaft.

3. In a clutch member for typewriters,-a

platen adapted to revolve with a shaft, a re-' cess in the end of said shaft, a casing loosely mounted adjacent the end of said shaft, a

thimble for holding said casing in assembled position on saidshaft, a ratchet mounted Copies of this patent may be obtained for upon said casing, a plunger adapted to slide in the recess in said shaft, dogs mounted in said plunger and adapted to engage said casing, whereby said ratchet will revolve with said platen and shaft, means for normally holding said dogs in engagement with said casing, and means for releasing said dogs from engaging said casing, whereby said ratchet may be turned independently of said platen.

4.. In a clutch for typewriters, a platen p 7 adapted to revolve with a shaft, a recess in urge the head 5 of the plunger back into its" the end of said shaft, a casing loosely mountt ed upon said shaft, said casing comprising two membersscrew mounted to a ratchet, a recess formed by the assembling of said members to said'ratchet, a plunger mounted to slide in the recess in said shaft, dogs 1 mounted in'said plunger, said dogs adapted to engage the sides of saidrecess formed by the members of said casing, whereby said ratchet will revolve with said platen, and

means for releasing said dogs from engage, ment with the recess formed by said members, whereby said platen may be turned in dependently of said ratchet.

5.. In a clutch for typewriters, a shaft supporting a platen'adapted to revolve there- -with, a recess in the end of said shaft, a casagainst the tension of said spring, whereby said dogs will be released from engagements with said casing to permitthe platen to turn independently of said ratchet.

In testimony whereof I have affixed my signature in the presence of two witnesses. MILLARD L. JOHNSTON;

l/Vitnesses: 1 s CHARLES O.v JONES, JAMES S. JOHNSTON.

five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

